Problem with WinHelp, Win95 vs NT

I have a HelpCommand call (i.e., WinHelp) in my program to show a particular
help topic at a particular time.

This works fine in Win95, but a user running NT is getting an intermittent
"Topic Not Found" message from Help, using the same help file and program.

Does anyone know of a difference between the two systems that would lead to
this anomaly?

Elliott
"I don't want to achieve immortality through my work.  I want to achieve
immortality through not dying." --Woody Allen